Abnormal Conditions, Emergencies and Accident Prevention
Core concepts
Recognise abnormal conditions early: low water level, high water level, foaming and priming, carryover, caustic embrittlement, scale and overheating, tube failure, shell leakage, flame failure, furnace explosion, pump failure, power failure, safety valve failure and fire or fuel leak.
Know the required response to low water: shut off fuel and air, do not feed water until the cause is known and the boiler is checked; if the crown sheet is uncovered, do not feed. For high water, stop feed, reduce firing, blow down carefully and check steam lines. For foaming, reduce load, blow down and check chemistry.
Emergency drills cover fire, fuel leak, explosion risk, electrical failure and evacuation. Accident prevention covers permits to work, isolation, lockout/tagout, confined space entry, PPE and housekeeping.
Traps
- Feeding water immediately into an overheated boiler, which can cause violent flashing.
- Confusing priming (carryover of water) with foaming (bubbles at surface).
- Assuming a flame failure device removes the need for purge.
- Forgetting that safety valve failure requires immediate shutdown.
Worked rule of thumb
Use the stop–check–act rule: on any abnormal condition, stop fuel first, then investigate, then act. Fuel is always the first thing removed.